Grip lifter



DQQ 1946- G. E. MOORE ETAL 2,413,366

GRIP LIFTER Filed Dec. 28, 1944 4 Sheets-Sheet 1 INVENTORS George E Moore and Q1! 5. Mill? 1946- G. E. MOORE ETAL 2,

GRIP LIFTER Filed Dec. 28 I944 4 Sheets-Sheet 2 Gear BY CZ mm" 3 Em Patented Dec. 3l, 1 946 Miller,

North Muskegon, Mich assignors to Manning, Maxwell J; Moore, Inc, Bridgeport, Coma, a corporation of New Jersey Application December 2 8, 1944; Serial No. 570,047

I Claims. crass-11c) This invention relates to weight actuated gr1l ping devices by means of which heavy objects;

such as plates, sheets, bars, and the like, may be lifted and moved about.

An object of this invention is to provide a strong, rugged device of this type in which the gripping forces are exerted by the load being lifted and are magnified by a compound leverage system to insure a firm grasp thereon.

Another object of this invention is to provide in a weight actuated grip lifter a latching device 'which looks the gripping laws in gripping position and holds them from releasing the object should the gripping device be relieved of the weight thereof as, for example, by engagement of the object with some resting surface.

A more detailed object of the invention is to provide a latching structure which may be easily released upon a conscious act of the operator.

A still further object 'of the invention is to provide an improved grip lifting device in which the gripping laws are detachably mounted for easy removal for repair and replacement.

.- An important object of this invention is to provide an improved form of gripping Jaw especially adapted to manufacturing processing ing thereof.

Other and more detailed oblects of this inven 5 tion will be apparent from the following disclosure of one embodiment thereof given for illustrative purposes with no intention of being limited to the specific form illustrated but ratherby the scope of the appended claims interpreted in the light of established legal precedence.

This invention resides substantially in the combination. construction, arrangement and relative location of parts as will be described in detail below.

In the accompanying drawings- Figure l is a side elevational view of one to of the grip lifting device embodying the subject matter of the invention. herein disclosed;

Figure 2 is a cross-sectional view taken on the line 2-2 of Figure l with a portion broken away;

Figure 3 is a side elevational view of a part comprising the fulcrum rod;

Figure 4 is a top plan view of the device with some parts removed;

Figure. 51s a detail broken view with some parts omitted showing a locking device for the latch;

Figure 6 is a cross-sectional view taken on the line 8-8 of Figure 5;

Figure 7 is a plan view of a modified form of locking device showing but a very small portion 1 the grip lifter; and

Figure 8 is'a cross-sectional view taken on the line 8-8 of Figure 'I. a I

in the mak- I z I The lifter comprises a plate-like main body portion Hi having, as illustrated, a central longitudinal passage H therethrough of cylindrical cross-sectional shape and a pair of downwardly divergent elongated slots i2 symmetrically disposed on opposite sides of the central axis. This element of the devicemay' be termed the-jaw r guide. The fulcrum rod clearly disclosed in Figure 3 is of T-shaped formation in which the apertured portion It forms the head and the portion it of cylindrical cross-section forms the stem.

A series of transverse serrations forming the teeth I! are formed in the stem It to provide the rack bar of the latching device, as will be described in more detail below.

The fulcrum rod lies between two pairs-of jaw levers II and It the relationship of which with respect to the jaw guide II will be clearest from Figure 4. The jaw lever pairs are pivotally mounted on the fulcrum rod by means of pivot pins l1 and II and the jaw levers are preferably provided at these pivotal supports with thickened hub orbushing portions I! and 20. The bearings for the pivot pins i1 and It as thus formed are preferably provided with some suitable form of lubricating device such as the grease gun fixtures 38. The stem ll of the fulcrum rod lies in the passage ll, asis clear from Figure 2. The upper ends of the jaw leverpairs i5 and It are provided with apertures to receive the roller pins 2| and 21 on which are rotatably mounted the rollers 23 and 24, respectively, which operate in the guide and actuating slots II in the main support II. The

support It) in transverse alignment with the passage II, as will be seen from Figure 2, in which is welded or otherwise secured a circular plate or disc 29 having a pair of parallel wings to on "which is pivotaily mounted,- by means of a pivot pin 3|, the latch lever 32. The pivot pin 3| may be secured in plac in any suitable manner, as, for example. by means of snap retaining rings best shown in Figure 4 at Ila. The upper end of the latch lever 32 is provided with a head or manual 33 having a recess therein in which one end of a compression spring 34 is seated by means of a buttonjl' having a cylindrical engaging face. The other end of the spring is seated in a recess in theadjacent wall of the support I. The lower end of the latch lever 32 is provided with a plurality of teeth 25 which may cooperate with the teeth 36 on the stem ll of the fulcrum rod through aligned apertures in the plate 29 and the adjacent wall of the support Ill. The wingslll and latch lever 32 are provided with apertures 32' which may be aligned when the latch lever is in retracted position through which a pin may be passed to put the latching mechanism out of use should conditions warrant.

- Lying in suitably shaped open sided aligned recesses in the gripping lever pairs l and ii are the generally cylindrical gripping jaws 31 which are locked therein by means of nuts and bolts 38. These gripping jaws can be easily removed by removing the nuts and bolts 38 for replacement and repair. Since the gripping jaws 31 are cylindrical they are locked in the lever pairs by the bolt 33 which lies in a longitudinal semicircular groove of the surface of each gripping jaw and in semicircular openings in the lever pairs l5 and I 6, as can be gathered from a study of Figure 2. The ends of the gripping jaws 31 are cut away, as shown in the drawings, so that the nuts thereon will lie substantially flush with the ends of the ripping jaws to protect them and, of course, will contact the outer faces of the lever pairs i5 and I 6, as is clear in Figure 2. The exposed facing areas of the gripping jaws 31 are provided with longitudinally extending grooves to form teeth or projections to insure non-slipping engagement with the object to be lifted. An important feature of the invention is the form of the gripping jaws to facilitate their manufacture. As is well known in this art, these gripping jaws are of hardened steel and it has been found that by making them of circular cross-section as shown that they may be more readily machined to final form and hardened to the desired temper with a minimum'tendency to develop fractures, fissures,- or other points of weakness such as are incident to the hardening of angularly shaped pieces.

While the operation of the device may be clear from the foregoing description, a brief explanation of its action in use will round out this disclosure. Devices of this type used for lifting heavy loads are usually used with-a crane, hoist, or other heavy duty lifting mechanism. The hook shackle 26 is, therefore, engaged on the hook of the crane or hoist and lowered'down over the edge of a plate, for example, to be lifted. The noses of the lever arm pairs 1 5 and I6 are rounded so as to be caused to move apart as they engage the 4 the greater the load imposed upon the device the greater the gripping action thereof on the load.

As the support ill moves with respect to the lever pairs l5 and i6, it will be seen that the teeth of the rack bar 36 move downwardly with respect to the cooperating teeth on the latch bar 32. These teeth are held in engagement by the action of the compression spring 34- on the upper end of the latch lever 32 so that each increment of relative movement is accumulated. so to speak. with the result that the parts are locked in maximum gripping relation. Should the plate being lifted by the device come to rest on any surface so that a portion or all of the load on the gripping device is removed, the gripping force exerted by the device is not relaxed because the latching lever holds the parts in the maximum position to which they have been extended. When it is desired to release the plate from the device, the manual 33 is pushed to break the engaging relation between the sets of teeth 35 and 38 to release the device so that it can be removed.

In order to avoid any dimculties in removing the grip lifter from an object after the latch has been released and to hold the gripping jaws in open position until the grip lifter has been properly applied to the object to be lifted, a locking attachment for the latch lever may be provided. Two forms of such an attachment are illustrated in Figures 5 to 8, inclusive. In the form of Figures 5 and 6, it will be seen that a small button 50 of elongated shape, as shown, is pivotally mounted on a screw 5| mounted in the main body plate or support in of the lifter. A spring 52 is interposed between the screw 5i and the button 50 to offer frictional resistance to the rotation thereof. As is clear from Figure 5, in the full line position the button 50 projects under the head or manual 33 of the latching top edge of the plate in the event they ar not sufliciently spaced to receive the plate. The separating action of the plate will cause rotation of these levers on the pivot pins l1 and I8 so that the gripping jaws 31 separate and the device may be lowered until the upper edge of the plate engages the exposed edge of the head I3 of the fulcrum rod. The crane is then reversed in its direction of movement so that the full weight of the device is 'taken by the hook shackle. There results a relative movement between the lever pairs i5 and i6 and attached parts of the support it], as a result of which the upper ends of the lever pairs l5 and I6 separate forcing the lower ends towards each other and moving the gripping jaws 31 into gripping engagement with the sides of the plate lying therebetween. As the device begins to pick up the load, this gripping action is increased and magnified by the compound leverage system of the structure so that lever 32 preventing it from moving in a position to disengage the ratchet teeth 36 on the stem H of the fulcrum rod. With this arrangement it will be seen that when the jaws are moved to full open position, as shown in Figure 1, the latching lever 32 may be retained in engaging position by rotating the button 50 so that it will project under the end 33 of the latching lever. With this arrangement the gripping jaws cannot close as they would tend to do due to their own weight. This facilitates positioning the grip lifter on the object to be lifted with the jaws open. When in position, button 50 may be turned to the dotted position shown in Figure 5 and the latching lever then manually released if it does not rclease itself so as to permit the grip levers' l5 and I6 to move into gripping position. Of course, the button 50 could be used for a similar purpose after the load is lifted but it has no real utility then because the load itself insures adequate gripping action.

A modified arrangement is shown in Figures 7 and 8 in which case a suitably shaped strap 53 is attached to the support in by means of screws, as shown, in the position of the button 50 of the previous modification. Slidably mounted in the strap is a U-shaped latching bar 54 which is frictionally resisted in movement by means of a spring 55 attached to the strap 53 by means of a rivet. As will be clear in Figure 8, the latching bar 54 is in a position to cooperate with the head 33 of the latching lever and is merely pushed upwardly to its other position to move it out of cooperative relationship with the latching lever. Thus the structure of Figures 7 and 8 is capable of performing the same functions as that shown in Figures 5 and 6.

From the above description it will be apparent to those skilled in the art that the subject matter of the invention is capable of embodiment in other physical forms. We desire, therefore, that the disclosure be taken purely in an illustrative sense.

What is claimed is:

1. In a grip lifting device, the combination comprising a body member having a pair of divergent camming faces and a longitudinal passage therein, a fulcrum rod slidably mounted in said passage, a pair of levers pivotally mounted, intermediate their ends, on said fulcrum rod, cam followers mounted on the levers at one end of each and engaging said camming faces, removable gripping jaws mounted on the levers at the other end of each in opposed relation, a latching lever pivotally mounted on said body member and cooperating with said fulcrum rod to .lock it in any position it assumes in said passage, a spring for biasing said locking lever in looking position, and means for preventing movement of the latching lever in unlatching direction.

2. In a grip lifting device, the combination comprising a body member having a pair of divergent camming faces and a longitudinal passage therein, a fulcrum rod slidabiy mounted in said passage, a pair of levers pivotally mounted,

intermediate'their ends, on said fulcrum rod, cam

followers mounted on the levers at one end of each and engaging said caming faces, removable gripping jaws mounted on the levers at the other end of each in opposed relation, a locking lever pivotally mounted on said member and projecting through an aperture in the wall thereof opening into said passage, teeth formed on said fulcrum rod for locking cooperation with said looking lever, and a shiftable member positionable under the locking lever to prevent disengagement with the teeth of the fulcrum rod.

6 3. In a grip lifting device, thecombination comprising a body member having a pair of divergent camming faces and a longitudinal passage therein, a fulcrum rod slidably mounted in said pas-sage, a pair of levers pivotally mounted,

intermediate their ends, on said fulcrum rod,

cam followers mounted on the levers at one end of each and engaging said camming faces, removable gripping jaws mounted on the levers at the other end of each in opposed relation, a locking lever pivotally mounted on said member and projecting through an aperture in the wall thereof opening into said passage, teeth formed on said fulcrum rod for locking cooperation with said locking lever, a spring for biasing said locking lever in locking position, and a movable button mounted on said support for movement under the end of the locking lever to prevent its movement in unlocking direction.

4. In a gripping device having a pair of mov- I so that the heads of the bolts lie in the recesses at one end of each jaw, and nuts threadedly engaging said bolts and lying in the recesses at the other ends of said jaws, the heads of the bolts and the nuts lying at least flush with the ends of the jaws.

5. In the combination of claim 4, said jaws and members having substantially semicircular aligned longitudinal grooves in which said bolts lie.

GEORGE E. MOORE. CARL E. MILLER. 

